Tissue blood perfusion measured using the thermal pulse decay (TPD) method

The temperature pulse decay method is discussed as a thermal method for the measurement of local tissue blood perfusion. It is based on the classic bio-heat equation proposed by Pennes (1948). For online measurements, a series solution of the theoretical model enables a fast evaluation of tissue perfusion. The small size of the thermistor bead used to deposit the heat pulse and measure the subsequent temperature decay reduces the errors due to the inexact formulation structure of the theoretical model while also minimizing the trauma caused to the tissue. Experiments performed in the liver and the kidney cortex of several animal species demonstrate that the TPD method provides realistic estimates of blood perfusion